The present invention generally relates to binoculars and, more particularly, to a binocular focusing mechanism for a binocular having generally parallel telescopes with movable optical elements.
Conventional binoculars have utilized various different types of focusing mechanisms including individually rotatable ocular lenses or eye pieces. Since this type of focusing mechanism is slow and difficult to use, many manufacturers have adopted the more efficient center-focusing binoculars having a wheel centrally mounted between two spaced apart telescopes each holding optical elements where the wheel is coupled by a bridge member to housings slidably mounted in the telescope bodies. With this arrangement, the wheel can be rotated to cause the housings to move relative to the bodies to bring about relative movement of the optical elements to achieve simultaneous focusing.
While center-focusing binoculars are common, they have several inherent problems making them less than fully satisfactory for effecting focus. For instance, the wheel is oftentimes out of reach unless one hand is shifted from a normal and naturally assumed gripping position to place a finger against the wheel, and this problem is even more pronounced for persons having small hands. As a result of this problem, users have experienced considerable difficulty in holding binoculars steady during focusing.
Moreover, with center-focusing binoculars of the wheel type, the wheel must usually be rotated to a significant degree. This requires further shifting of the hands as the fingers are required to either ride up and over the center of the binocular as the wheel is rotated or, alternatively, the finger must frequently be removed from the wheel and then again engage the wheel at a lower point on the circumference after the wheel has been rotated only by a very slight amount. While attempts have been made to provide a wheel that focuses in a rapid manner, the fact remains that the use of a wheel does not adequately take into account the physiological effects on the user.
In view of these and other problems, it has remained to provide a binocular focusing mechanism that is fully satisfactory.